Belt retractors are generally known as components of occupant restraint systems. They generally comprise a load limiting element and optionally have a belt tensioner drive which tightens a safety belt of the occupant in case of an impending vehicle impact, by driving a belt spool of the belt retractor in the belt up-winding direction. The load limiting element makes a withdrawal of belt webbing possible in a locking position of the belt spool, in order to limit a physical stressing of the occupant.
If, in the case of restraint, the belt webbing has a belt slack, e.g. owing to a failure of the belt tensioner, a certain forward displacement of the occupant, for instance towards an instrument panel or a steering wheel, is already possible. So that the forward displacement of the occupant does not become too great, a release of belt webbing by the load limiter is frequently undesired in these restraint situations. The belt retractor should therefore not permit any load limitation, i.e. any withdrawal of belt webbing on the belt spool, for example in the case of a failure of a tensioning system which may be provided in the belt retractor, on a belt buckle or on an end fitting.
It is an object of the invention to provide a belt retractor with a load limiting function, the load limiter of the belt retractor being “connectable” only in predeterminable restraint situations, for example in restraint situations with belt tensioning.